Background and aims: The major risk factors for acute hepatitis B (AHB) in China and the viral factors determining chronicification of AHB remain largely unknown.
Methods: Epidemiological studies within a population-based surveillance for AHB in adults were performed in Shanghai, China, including 294 cases, 588 matched controls and 572 family members of the cases.
Results: Invasive medical procedures, household contact with hepatitis B virus (HBV) carriers, body care and beauty treatments, and absent HBV vaccination were independently associated with AHB. Among those risks, pedicure in bath centers were emerging. Sixty-eight of 128 patients with AHB were genotyped including 33 with HBV B2 and 35 with HBV C2. Twenty-five (8.50%) of the 294 cases, including 20 with HBV C2 and 5 with HBV B2 (p = 0.013), progressed to chronic infection. Multivariate analysis showed that HBV C2 was independently associated with chronicification of AHB. Patients with HBV B2 were younger and with higher proportion in female than those with HBV C2. The prevalence of HBV B2 was higher in the patients than in neighborhood chronic carriers. The chronic carriers with HBV B2 showed higher viral loads, higher hepatitis B e antigen (HBeAg) seropositivity, and with higher proportion in male than those with HBV C2, implying that sexual contact plays a role in HBV B2 transmission. Phylogenetic analysis showed that HBV C2 was frequently involved in household transmissions.
Conclusions: Despite lower viral load and HBeAg status in the chronic carriers, HBV C2 was more prone to causing chronic infection than HBV B2.